Virus meningo-encephalitis in Slovenia.

The authors describe the main epidemiological features of the meningo-encephalitis observed in Slovenia since 1946. It is endemic there with occasional epidemic outbreaks; close study has been made of the epidemic which occurred in 1953. The disease is markedly seasonal, 95% of all cases in 1953 occurring from May to September. Another characteristic feature is the mention of tick bites in a very large number of case-histories; although the Slovenian tick fauna has not yet been systematically investigated, the generally incriminated vector is the tick Ixodes ricinus. In close association with this feature, the disease appears primarily among persons whose work lies in the woods where the ticks are found. This consequently affects the age distribution of patients, 56.2% of whom in 1953 were 11-30 years old. No spread of infection from person to person has been noted.The disease closely resembles the tick encephalitis observed in Czechoslovakia and the meningo-encephalitis described in western Russia and Austria. The authors consider it probable that the virus circulates in enzootic foci between rodents and ticks and that man is accidentally infected.